From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F4075C388F9 for ; Wed, 21 Oct 2020 10:02:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A20C121789 for ; Wed, 21 Oct 2020 10:02:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="hPrRgAJd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2409357AbgJUKCn (ORCPT ); Wed, 21 Oct 2020 06:02:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405683AbgJUKCn (ORCPT ); Wed, 21 Oct 2020 06:02:43 -0400 Received: from mail-qv1-xf44.google.com (mail-qv1-xf44.google.com [IPv6:2607:f8b0:4864:20::f44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 27152C0613D2 for ; Wed, 21 Oct 2020 03:02:43 -0700 (PDT) Received: by mail-qv1-xf44.google.com with SMTP id t20so731137qvv.8 for ; Wed, 21 Oct 2020 03:02:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=xnb4S5hkq6BURUu/rhTqWY2zD92VHkscM9v42h9u1pw=; b=hPrRgAJdSC9qgVYpqs58Djiy9jW7qX/2bOcA8PsLyLnk3K1IGTECBQ/KiluBPINYDQ qZr5HUze1+k8N4bzqGycnnB+OTxTqaO/om2fNwBIUYiQEP0RvCVUhhVMzVnu7bdh+FaX 5VCndHuJIIwBX51m5oEzhCp7InBg1Mh5BkLffXNCXvQWEE3OlSLfHj/1mIGnzUoIAxX+ xKm/sz4YuuMm+Kz670DVwS25DzZI/nbKmlnEOooY7MfRJrUDRvrRAdPwZqijX6Tv00Zx pk3Qat3/7503P5DLdrupPPH7m+tr/vnMAMNfWv1MQQOcW1OgKuQWM1a2NyUJnLu8gwtM Lf9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=xnb4S5hkq6BURUu/rhTqWY2zD92VHkscM9v42h9u1pw=; b=LiBomvahleu+Kz8rDo3oidVF0aG1rxMq0HZWSgd8Ek3TUYLbMd1lCYe9Ncp963mJaC PlYfiTLVpw7V1TQKreTR+FuTXk9TbhCng4onT6qaPQBRwHdANqQOzIysOFAk7cCNVvYy q0CxuIBhkbIghWpNOHFmGymii49aLZVyzvXxag8ykpD6IlIuOUqBiqUCGAfRZVH+JmLb ZPmn6f1oYeRhaW0CN/Q71RF3okBxfXyX0jgzppH8RJ2sIT/xu4hHfa24IlDCGbWp9tdc KDqDqGZ8DbzV0BIpZgu4QRYuQqJ1gVzkNFWqnypy+2VICraQxuGgSVPMfGiw2bOp/Ez6 eMxQ== X-Gm-Message-State: AOAM532T1epRSgvxPAKtZPl6IrxmUk/Lt+x7pdRM1wb8a0TjDXNzsjJH MVmch0iXcE+iNH0Ws5ajH9M9caYTKdgixeGqIcLfZQ== X-Google-Smtp-Source: ABdhPJxh8i5rMjF7h2nMwGGOMnC8tgzLYSjRpt6RrRJ5khqmyTmwJYQMBrV92PQMbIU+pniLsWEpTce2a2RX9VFcM/8= X-Received: by 2002:a0c:ba2a:: with SMTP id w42mr1949961qvf.23.1603274561877; Wed, 21 Oct 2020 03:02:41 -0700 (PDT) MIME-Version: 1.0 References: <00000000000010295205b1c553d5@google.com> <1039be9b-ddb9-4f76-fda3-55d10f0bd286@kernel.dk> In-Reply-To: <1039be9b-ddb9-4f76-fda3-55d10f0bd286@kernel.dk> From: Dmitry Vyukov Date: Wed, 21 Oct 2020 12:02:30 +0200 Message-ID: Subject: Re: WARNING: suspicious RCU usage in io_init_identity To: Jens Axboe Cc: Qian Cai , io-uring@vger.kernel.org, linux-fsdevel , LKML , syzkaller-bugs , Al Viro , syzbot Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Fri, Oct 16, 2020 at 5:05 PM Jens Axboe wrote: > > On 10/16/20 9:02 AM, Qian Cai wrote: > > On Fri, 2020-10-16 at 01:12 -0700, syzbot wrote: > >> Hello, > >> > >> syzbot found the following issue on: > >> > >> HEAD commit: b2926c10 Add linux-next specific files for 20201016 > >> git tree: linux-next > >> console output: https://syzkaller.appspot.com/x/log.txt?x=12fc877f900000 > >> kernel config: https://syzkaller.appspot.com/x/.config?x=6160209582f55fb1 > >> dashboard link: https://syzkaller.appspot.com/bug?extid=4596e1fcf98efa7d1745 > >> compiler: gcc (GCC) 10.1.0-syz 20200507 > >> > >> Unfortunately, I don't have any reproducer for this issue yet. > >> > >> IMPORTANT: if you fix the issue, please add the following tag to the commit: > >> Reported-by: syzbot+4596e1fcf98efa7d1745@syzkaller.appspotmail.com > >> > >> ============================= > >> WARNING: suspicious RCU usage > >> 5.9.0-next-20201016-syzkaller #0 Not tainted > >> ----------------------------- > >> include/linux/cgroup.h:494 suspicious rcu_dereference_check() usage! > > > > Introduced by the linux-next commits: > > > > 07950f53f85b ("io_uring: COW io_identity on mismatch") > > > > Can't find the patchset was posted anywhere. Anyway, this should fix it? > > It's just in testing... I already folded in this change. Now that it's in linux-next we can close this report: #syz fix: io_uring: COW io_identity on mismatch